Triple Olympic champion Usain Bolt is targeting the 9.4 second barrier for the 100m after setting a new world record at the World Championships.
The 22-year-old recorded a time of 9.58 seconds as he raced to a sensational victory in Berlin on Sunday.
Bolt shaved 0.11 off the time he set at the 2008 Olympics in Beijing.
"I think it will stop at 9.4 but you never know," said the Jamaican. "I don't run for world records. I'll just keep on working."

American Tyson Gay finished second in a time of 9.71, with Jamaica's Asafa Powell claiming bronze in 9.84.
"The aim was just to come and execute because it was going to be a tough race," added Bolt, who will also compete in the 200m.

"I got a pretty good start. I was there at 20 metres and that was it."
**** the previous 100m world champion, was not surprised that Bolt broke the 9.6 seconds barrier.
"I've been telling you someone could run 9.5. I'm happy he did it," said the American, who has been troubled by a groin injury.
"It showed a human can take it to another level. Unfortunately, I wasn't the one to do it but I still have confidence I can do it one day."
Gay's time in the final was the fastest by an American - and he added: "I ran the best I could but it was not enough.
"I believe I put in a championship performance and I am very pleased with the national record."
"I showed a lot of heart. I didn't complain about my groin injury. I put it together the best I could."
If Gay's groin injury does allow him to compete in the 200m he is expected to come up against Bolt again in Thursday's final.
The heats start on Tuesday and Bolt, world record holder at that distance, said: "There'll be no partying for me ahead of Tuesday. I'll rest up as always."
Following the championships in Berlin, Gay will run the 100m event at the British Grand Prix in Gateshead on 31 August, organisers confirmed.